import React, { Component } from 'react'
import PropTypes from 'prop-types'
import {nanoid} from 'nanoid'
import './index.css'

export default class Header extends Component {
  // 对接收的props进行类型、必要性的限制
  static propTypes = {
    addTodo: PropTypes.func.isRequired
  }

  // 处理输入框变化的回调
  handleKeyUp = (event) => {
    // 解构赋值获取target, keyCode
    const { target, keyCode } = event
    // 判断是否是回车
    if (keyCode !== 13) return
    // 添加的todo不能为空
    if (target.value.trim() === '') {
      alert('输入的todo不能为空')
      return
    }
    // 准备好一个todo对象
    const todoObj = { id: nanoid(), name: target.value, done: false }
    console.log(todoObj);
    // 将todoObj传递给APP
    this.props.addTodo(todoObj)
    // 清空输入框
    target.value = ''
  }
  render() {
    return (
      <div className="todo-header">
        <input type="text" placeholder="请输入你的任务名称，按回车键确认" onKeyUp={this.handleKeyUp} />
      </div>
    )
  }
}
